Did he have the cachet in ‘16 to defeat Monroe, though? IIRC Monroe was well known to be Madison’s preferred successor
Reading Lynn W. Turner's chapter on "The Elections of 1816 and 1820" in Arthur M. Schelsinger, Jr., Fred L. Israel, and William P. Hansen (eds.), *History of American Presidential Elections 1789-1968* (1971) it really does appear that Crawford could have had the nomination if he had wanted it. (You have to remember that some Republicans were getting tired of the Virginia dynasty--after all, there were other states in the Union...)
p. 305: "The threat represented by William H. Crawford was serious. It served to remind citizens of another blemish in Monroe's record--namely, that he had listened for some time in 1808 to the siren song of revolt as piped by John Randolph and the other 'Quidites' against the dynastic succession of Madison. He could therefore hardly complain now that dissident Republicans in New York and the South were rallying behind the vigorous and younger Georgian. Sentiment for Crawford was so strong in the winter that those who yearned for harmony in the Republican ranks expressed alarm at 'the measures resorted to, to divide the friends of the late war.' One of Monroe's correspondents voiced the hope 'that you and William Crawford will be both so truly great, as not to suffer your friendships to be impaired thereby.'
"Perhaps there did exist such an element of true greatness in Crawford's composition, although more cynical observers were convinced that he was induced to withdraw from the race in 1816 by the promise of support for the succession in 1824. A Monroe supporter, Senator Abner Lacock of Pennsylvania, later admitted to a newspaper publisher that he had voluntarily called upon the Secretary of War in early March and asked him to renounce his candidacy. Lacock had argued for party loyalty but had also pointed out that Crawford was a young man with plenty of time for a later turn at the Presidency. The Georgian, Lacock reported, had replied that his own feelings would not permit him to oppose Monroe for office. Before the second caucus met on March 16, Senators Charles Tait and William Bibb of Georgia, friends of Crawford, spread the word that the Secretary of War could not run against so venerable a figure as the Secretary of State. This statement was a little condescending, perhaps, but capable of translation into a spirit of loyal and noble forbearance. Unfortunately, the friends of Crawford bungled the rest of the job. They were supposed to have attended the caucus, made a formal statement of Crawford's renunciation, voted for Monroe, and explained the whole heroic procedure in the Government press. Instead, they absented themselves from the caucus, which proceeded to nominate Monroe by 65 votes, a narrow majority of 11 over the 54 cast by stubborn Crawford partisans from New York, New Jersey, North Carolina, Georgia, and Kentucky. Had all of the Georgian's supporters from among the twenty-two Republicans been present and voted, James Monroe might never have become President of the United States."
(You may note that Turner writes about the March 16 caucus as the "second caucus." On March 10, an unknown person posted an invitation to Republican members of Congress to meet on March 12 to make the necessary nominations. At the appointed time, only 58 of the 142 Republican members appeared. This was obviously too small a number to give approval to even a pre-determined choice, so Jeremiah Morrow of Ohio, chairman of the rump session, was persuaded to issue a more official call for a Republican caucus on March 16. Turner thinks the low attendance on March 12, while perhaps partly motivated by growing opposition to the whole caucus system, was primarily a matter of Monroe-ites failing to attend because they thought the caucus might nominate Crawford. "It would have been logical enough... for Monroe's adherents to have tried to avoid a showdown, and for Crawford's friends to take the lead by making the anonymous call for a caucus on March 12. Monroe's followers would have ignored the call, thus accounting for the poor attendance, but since their hands had been forced they would have attempted to rally all their strength for the second caucus. Its outcome confirms the reliability of this hypothesis. This is also the way the newspapers interpreted events." p. 303)